Understanding pain biology changes the way people think about pain, reduces its threat value and improves their management of it.
David Butler & Lorimer Moseley, Explain Pain
Chapter 5 provided the complex foundational elements of pain science. In this chapter, we share how clinicians can apply this knowledge to better manage patients.1 Being a clinician would be straightforward if the location of pain always revealed the precise area of pathology and pain had a tissue basis. But this is commonly not the case!
It is useful to consider the contributions to a patient’s pain. For example, is there peripheral sensitisation? Is there central sensitisation? Is there referral? Are there cortical contributions? Are there changes in cortical representations? No matter what the answer to these questions, pain is a sign that the brain is urging protection. Identifying the relative importance of different contributions allows you to target your treatment accordingly.
Let’s consider a patient with longstanding back pain. Historically, clinicians developed a list of differential diagnoses to classify injury or disease. In this case the options include muscle strain, disc injury or facet joint injury. Working from such a list of differential diagnoses relies on several assumptions. First, that knowledge of the affected structure is important to the assessment and diagnosis. Second, that it is possible to accurately confirm the diagnosis (i.e. that a gold standard exists). Third, that making a tissue diagnosis will inform treatment. Contrary to these 1980s opinions, none of those assumptions appear correct today.
A complementary approach is to consider an over-arching classification (e.g. ‘the patient had an episode of back pain’) that focuses on the pain experience and contributing factors as a distinct clinical entity. With this foundation, the clinician can add information about the state of specific anatomical structures and determine the best treatment approach (which may change over time).
This broader perspective of painful events, which encourages assessment by body region and type of threat, is based on the neuroscience that body movements are represented on motor homunculi and body surfaces are represented on sensory homunculi (Fig. 6.1). While the chapters of this book are arranged to permit region-specific assessment and treatment of what we consider predominantly nociceptive-driven (or input-dominated) presentations, this chapter aims to help clinicians to know when to consider centrally dominated pain in their assessment and management. So, what is meant by ‘input-dominated pain’ and ‘centrally dominated pain’?
Motor and sensory homunculi
Let’s begin with the most common type of pain that brings the patient to a clinician in this field—pain from a musculoskeletal injury. This is ‘input-dominated pain’ and it is distinguished from ‘centrally dominated pain’ (discussed in the next section). When learning about concepts like this, it ...